Yes, correct grammer is the most important thing in life.
Like, in HS, especially history classes, the concepts were never ever important, it was the exact DATES that were all important. Nobody cares what started the CivilWar, but what was really IMPORTANT was....what was the date of the start?
Just like history of WW11. Teachers never cared about the events that led to the war, they only cared about what DATE was the time the Germans first invaded Poland.